Downhole devices, associated apparatus and methods

A downhole device comprising:

• a generating material having a fluid contact surface, that contact surface being configured to be in contact with a fluid downhole, and the generating material being configured to generate an electric charge at the generating material in response a fluid at the contact surface;
• the device further comprising
• a signal source configured to provide a signal in response to a generated electric charge at the generating material;
• a flow control mechanism in communication with the signal source, the flow control mechanism being configured to operate responsive to signals being provided from the signal source and in response to the generated electric charge at the generating material, wherein the flow control mechanism comprises an activation device, the activation device comprising,
• a retainer configured to retain the flow control mechanism in a particular configuration, and to activate upon receipt of a signal from the signal source so as to release the flow control mechanism, wherein the retainer comprises a conducting sacrificial element configured such that current from the signal passes through the conducting sacrificial element, and further configured such that when a rate of charge flowing through the conducting sacrificial element exceeds a particular threshold, a structural integrity of the conducting sacrificial element decreases to allow activation of the flow control mechanism;
• and,
• a biasing mechanism configured to assist with operable opening/closing of the flow control mechanism.